Kinetics of thermal decomposition of ε-hexanitrohexaazaisowurtzitane by TG-DSC-MS-FTIR

Thermal decomposition of ε-hexanitrohexaazaisowurtzitane (HNIW) was studied by thermogravimetry-differential scanning calorimetry-mass spectrometry-Fourier transform infrared spectroscopy (TG-DSC-MS-FTIR) simultaneous analysis. It has been shown that there is a crystal transition point for ε-HNIW, and only a single decomposition process has been observed for HNIW. The kinetic parameters of thermal decomposition of HNIW were obtained by Kissinger and Flynn-Wall-Ozawa methods, indicating that HNIW has the higher reactivity compared to the other nitramines. The HNIW decomposition mechanism demonstrated by the non-isothermal kinetics conformed to Avrami-Erofeev equation with the factor of nucleus growth of n=1/3 and the conversion degree of α from 0.1 to 0.7. The MS and FTIR analyses indicated that the thermal decomposition of HNIW favors N-N bond cleavage over C-N bond cleavage as the rate determining step.